Model for electrification of urban public transport lines with supercapacitor buses: A case study of Belgrade

In this paper, a cost-oriented model for implementing e-buses equipped with supercapacitors in urban public transport was developed and tested. This model simultaneously determines the optimal locations for fast charger installation, their power ratings, capacity of supercapacitors, e-bus charging schedules in operation, and the amount of electricity transmitted to e-buses by chargers. IGNITE simulation software was used for modeling and simulating e-bus operation. The model was tested and validated with actual data from four bus lines in Belgrade (Serbia), presently with diesel-powered standard buses in operation, resulting in cost efficient solutions. Comparative analysis of implementation costs of e-buses with supercapacitors and LFP batteries was conducted. A sensitivity analysis of solutions was performed using both actual energy consumption data (based on recorded speed data, terrain configuration, and auxiliaries consumption impact), and average energy consumption. The sensitivity analysis demonstrated that input data quality significantly affects obtained solutions, as well as the sustainability and functionality of the urban public transport system. The impact of maximum e-bus charging times at bus stops and termini on passenger comfort was also considered, along with the impact of energy savings on the total implementation costs of supercapacitor e-buses.